The wireless spectrum is heavily segmented. For a given frequency band, a wireless provider may only have 20 MHz of the frequency spectrum out of the whole band. Wireless base transceiver stations (BTSs) have filters to interface with the antenna. Filters in each BTS match with the frequency spectrum possessed by the wireless provider. Therefore many types of filters may be used in a given wireless service provider's network. Filters are large and heavy, however, accounting for approximately 20% of the BTS form factor. Furthermore, current base stations with fixed bandpass filters offer very limited upgradability once installed in the field.
Tunable filters can reduce the numbers of types filters used in a given network, and simplify logistic management. Tunable filter technology generally allows a base station to be reconfigured/upgraded after installation. Most tunable filters in BTSs use a mechanical motor to drive a tuning mechanism to change the filter's frequency. The mechanical motor and tuning mechanism increase filter size and may cause reliability issues.